As 3D televisions (3DTV) have come into widespread use, 3D video content has come into widespread use and 3D video content has been transmitted through a digital broadcast.
In general, 3D video provides a stereoscopic effect using the principle of stereovision. Since a human feels a perspective effect through binocular parallax due to an interval between the eyes spaced apart from each other by about 65 mm, 3D video is provided such that a left eye and a right eye view respective plan images, thereby providing a stereoscopic effect and a perspective effect.
Examples of a 3D video display method include a stereoscopic method, a volumetric method, a holographic method, etc. In the stereoscopic method, a left view image to be viewed by a left eye and a right view image to be viewed by a right eye are provided and the left eye and the right eye respectively view the left view image and the right view image through polarized glasses or a display device, thereby perceiving a 3D video effect.
In case of stereoscopic 3D video content, when two similar videos of different views are transmitted, a receiver uses a method of displaying 3D video using the two videos. At this time, the two similar videos of the different views may be transmitted via an existing broadcast channel or separately transmitted via the existing broadcast channel and a separate transmission channel. In this case, the receiver should receive signal information of two videos forming a pair in order to display the two videos as 3D video. When such information is not received, a left-view image and a right-view image forming 3D video may not be distinguished such that the 3D video is not restored. In addition, it is not possible to check a synchronization time of the left-view image and the right-view image and when 3D video can be displayed.